среда, 15 августа 2018 г.

Meteor Activity Outlook for 11-17 August 2018

Meteor near San Diego, CA – © slworking2, August 13th, 2017

Canon EOS 6D, 15mm, ƒ/2.8, 15s, ISO3200)

During this period the moon will reach its new phase on Saturday August 11th. At that time the moon will lie near the sun in the sky and will be invisible at night. As the week progresses the waxing crescent moon will enter the evening sky but will not cause much interference for meteor observers, especially during the more active morning hours. The estimated total hourly meteor rates for evening observers this week is near 7 as seen from mid-northern latitudes and also 5 for those viewing from subtropical southern latitudes (25S). For morning observers the estimated total hourly rates should be near 60 for those viewing from mid-northern latitudes and also 30 for those viewing from subtropical southern latitudes (25S). The actual rates will also depend on factors such as personal light and motion perception, local weather conditions, alertness and experience in watching meteor activity. Note that the hourly rates listed below are estimates as viewed from dark sky sites away from urban light sources. Observers viewing from urban areas will see less activity as only the brighter meteors will be visible from such locations.

The radiant (the area of the sky where meteors appear to shoot from) positions and rates listed below are exact for Saturday night/Sunday morning August 11/12. These positions do not change greatly day to day so the listed coordinates may be used during this entire period. Most star atlases (available at science stores and planetariums) will provide maps with grid lines of the celestial coordinates so that you may find out exactly where these positions are located in the sky. A planisphere or computer planetarium program is also useful in showing the sky at any time of night on any date of the year. Activity from each radiant is best seen when it is positioned highest in the sky, either due north or south along the meridian, depending on your latitude. It must be remembered that meteor activity is rarely seen at the radiant position. Rather they shoot outwards from the radiant so it is best to center your field of view so that the radiant lies near the edge and not the center. Viewing there will allow you to easily trace the path of each meteor back to the radiant (if it is a shower member) or in another direction if it is a sporadic. Meteor activity is not seen from radiants that are located far below the horizon. The positions below are listed in a west to east manner in order of right ascension (celestial longitude). The positions listed first are located further west therefore are accessible earlier in the night while those listed further down the list rise later in the night.

Radiant Positions at 22:00 LST

Radiant Positions at 22:00

Local Summer Time

Radiant Positions at 01:00 LST

Radiant Positions at 0100

Local Summer Time

Radiant Positions at 4:00 LsT

Radiant Positions at 04:00

Local Summer Time

These sources of meteoric activity are expected to be active this week.

The August Draconids (AUD) were discovered by Zdenek Sekanina in his study of meteor streams using radio methods. This stream is active from August 13-19 with maximum activity occurring on the 16th. The radiant is currently located at 18:04 (271) +59, which places it in southern Draco, 8 degrees north of the 2nd magnitude star known as Eltanin (gamma Draconis). This radiant is best placed near 2200 local summer time (LST), when it lies on the meridian and is located highest in the sky. With an entry velocity of 21 km/sec., the average August Draconid meteor would be of slow velocity. Rates this week are expected to be less than 1 per hour no matter your location

The kappa Cygnids (KCG) should be active from a radiant located near 18:59 (285) +50. This area of the sky lies in southern Draco, 4 degrees southwest of the 4th magnitude star known as kappa Cygni. This radiant is best placed near 2300 LST, when it lies on the meridian and is located highest in the sky. Rates should be near 1 per hour as seen from mid-northern latitudes. Unfortunately these meteors are not well seen from the southern hemisphere due to their low radiant altitude. With an entry velocity of 21 km/sec., the average meteor from this source would be of slow velocity.

The center of the large Anthelion (ANT) radiant is currently located at 22:08 (332) -12. This position lies in western Aquarius, 2 degrees north of the 4th magnitude star known as iota Aquarii. Due to the large size of this radiant, Anthelion activity may also appear from eastern Capricornus as well as Aquarius. This radiant is best placed near 0200 LST, when it lies on the meridian and is located highest in the sky. Hourly rates at this time should be near 2 as seen from mid-northern latitudes and 3 as seen from tropical southern latitudes. With an entry velocity of 30 km/sec., the average Anthelion meteor would be of medium-slow velocity.

The Northern delta Aquariids (NDA) are active from July 23 through August 27. The radiant is currently located at 23:04 (346) +02. This position is located in western Pisces, 3 degrees west of the 4th magnitude star known as gamma Piscium. Maximum activity is on August 14, so hourly rates should be near 1 per hour no matter your location. The radiant is best placed near 0300 LST, when it lies highest in the sky. With an entry velocity of 38 km/sec., these meteors would be of medium velocities. This shower seems to be a continuation of the Northern June Aquilids, which had been active since early June.

The Southern Delta Aquariids (SDA) are active from a radiant located at 23:30 (353) -12. This position is located in eastern Aquarius directly between the faint stars known as psi and omega Aquarii. Hourly rates are now only 1 per hour as seen from the northern hemisphere and 2 per hour for those south of the equator. The radiant is best placed near 0400 LST, when it lies highest in the sky. With an entry velocity of 41 km/sec., most activity from this radiant would be of average velocities.

The Piscids Austrinids (PAU) are an obscure shower, not well seen from the northern hemisphere. Recent studies by the IMO Video Network shows no activity at all. Other studies have indicated that this shower is active later than previously thought. We will go along with that idea until more information is available. It is now thought that this radiant is active from July 30 through August 18, with maximum activity occurring on the 8th. Using these parameters, the current position of the radiant would be 23:44 (356) -19. This area of the sky is located in southern Aquarius, near the faint stars known as 106 and 107 Aquarii. The radiant is best placed near 0400 LST, when it lies highest in the sky. Current rates would most likely be less than 1 per hour, no matter your location. With an entry velocity of 44km/sec., most activity from this radiant would be of average velocities.

The beta Hydrusids (HDY) are only known through an outburst reported on August 17, 1985. Activity from this stream is seen from August 15-19 with maximum activity occurring on the 17th. At maximum the radiant lies at 02:25 (036) -75, which places it in southern Hydrus between the bright stars known as beta and gamma Hydri. Due to the far southern location, these meteors are not visible from the northern hemisphere. For southern observers, this area of the sky is best seen during the last dark hour before dawn when the radiant lies highest in a dark sky. Current rates are expected to be less than 1 per hour during this period no matter your location. With an entry velocity of 23 km/sec., the average meteor from this source would be of slow velocity.

The eta Eridanids (ERI) were discovered by Japanese observers back in 2001. Activity from this stream is seen from July 23 though September 17 with maximum activity occurring on August 11. The radiant currently lies at 03:00 (045) -12, which places it in western Eridanus, 2 degrees southeast of the 4th magnitude star known as Azha (eta Eridani). This area of the sky is best seen during the last dark hour before dawn when the radiant lies highest in a dark sky. Current rates are expected to near 1 per hour as seen from the northern hemisphere and near 2 per hour as seen from south of the equator. With an entry velocity of 65 km/sec., the average meteor from this source would be of swift velocity.

The Perseids (PER) reach maximum activity on August 12/13 from a radiant located at 03:12 (048) +57. This position lies in northern Perseus, 3 degrees northeast of the 3rd magnitude star known as gamma Persei. This area of the sky is best placed for viewing during the last dark hour before dawn when it lies highest in the sky. Rates from dark sky sites are expected to be near 60 per hour as seen from the northern hemisphere and 20 as seen from south of the equator. Unfortunately these meteors are not well seen from the southern hemisphere as the numbers decrease to zero from mid-southern latitudes (S45). With an entry velocity of 59 km/sec., the average meteor from this source would be of swift velocity.

As seen from the mid-northern hemisphere (45N) one would expect to see approximately 14 sporadic meteors per hour during the last hour before dawn as seen from rural observing sites. Evening rates would be near 4 per hour. As seen from the tropical southern latitudes (25S), morning rates would be near 10 per hour as seen from rural observing sites and 3 per hour during the evening hours. Locations between these two extremes would see activity between the listed figures.

The list below offers the information from above in tabular form. Rates and positions are exact for Saturday night/Sunday morning except where noted in the shower descriptions.

RA (RA in Deg.) DEC Km/Sec Local Summer Time North-South
August Draconids (AUD) Aug 16 18:04 (271) +59 21 22:00 <1 – <1 II
kappa Cygnids (KCG) Aug 13 18:59 (285) +50 21 23:00 1 – <1 II
Anthelions (ANT) 22:08 (332) -12 30 02:00 2 – 3 III
Northern delta Aquariids (NDA) Aug 14 23:04 (346) +02 38 03:00 1 – 1 IV
Southern delta Aquariids (SDA) Jul 30 23:30 (353) -12 41 04:00 1 – 2 I
Piscids Austrinids (PAU) Aug 08 23:44 (356) -19 44 04:00 <1 – <1 IV
beta Hydrusids (HDY) Aug 17 02:25 (036) -75 23 06:00 0 – <1 III
eta Eridanids (ERI) Aug 11 03:00 (045) -12 65 07:00 1 – 2 IV
Perseids (PER) Aug 13 03:12 (048) +57 59 07:00 40 – 15 I

Painted Hills, Northwest United States | #Geology…

Painted Hills, Northwest United States | #Geology #GeologyPage

Painted Hills, in the northwest United States, is one of the three units of the John Day Fossil Beds National Monument, located in Wheeler County, Oregon.

Read more & More Photos: http://www.geologypage.com/2016/05/painted-hills-northwest-united-states.html

Geology Page


Closest asteroid flyby of the year: 2018 PD20 flew past Earth at 0.09 LD

A newly discovered asteroid designated 2018 PD20 flew past Earth at a very close distance of 0.09 LD / 0.00022 AU (33 210 km / 20 636 miles) at 14:31 UTC on August 10, 2018.

This near-Earth object belongs to the Apollo group of asteroids and its estimated diameter is between 8.9 and 20 m (29 and 65 feet).

It was first observed at 13:05 UTC on August 11 at ATLAS-MLO, Mauna Loa, one day after its closest approach.

Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Close-Approach Data ]

This is the 39th known asteroid to flyby Earth within 1 lunar distance since the start of the year and the 40th discovered (within 1 LD), including 2018 LA which was discovered some 8 hours before it hit Botswana on June 2.

This was also the closest flyby of any known asteroid since the start of the year, right after 2018 BD of January 18 at 0.00026 AU.

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Asteroid 2018 PD20 at Minor Planet Center; at CNEOS

Featured image: The green line indicates the object’s apparent motion relative to the Earth, and the bright green marks are the object’s location at approximately half hour intervals. The Moon’s orbit is grey. The blue arrow points in the direction of Earth’s motion and the yellow arrow points toward the Sun. Credit: Minor Planet Center

An Egg-ceptional Vaccine Summer may seem like a strange time…

An Egg-ceptional Vaccine

Summer may seem like a strange time to be thinking about the flu but it’s a good time to talk about the flu vaccine, which is usually available from September. Because the flu virus continually evolves, every flu season needs a new vaccine. Yet the vaccine for the 2016-17 season wasn’t very effective, and scientists think they know why. Vaccines are made from flu virus proteins that are mass-produced in chicken eggs. When injected into a human, these proteins trigger an immune response that protects against the real virus later on. The flu protein in this image (haemagglutinin) recently evolved a tiny change in its structure that leaves it susceptible to chemical modification in the eggs, making it less likely to be recognised by the immune system and reducing its effectiveness as a vaccine. So using vaccines produced through other methods might provide better protection for the most vulnerable people.

August is National Immunization Awareness Month

Written by Kat Arney

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Meteorite bombardment likely to have created the Earth’s oldest rocks

Scientists have found that 4.02 billion year old silica-rich felsic rocks from the Acasta River, Canada – the oldest rock formation known on Earth – probably formed at high temperatures and at a surprisingly shallow depth of the planet’s nascent crust. The high temperatures needed to melt the shallow crust were likely caused by a meteorite bombardment around half a billion years after the planet formed. This melted the iron-rich crust and formed the granites we see today. These results are presented for the first time at the Goldschmidt conference in Boston on 14 August, following publication in the peer-reviewed journal Nature Geoscience.

Meteorite bombardment likely to have created the Earth's oldest rocks
Credit: NASA’s Goddard Space Flight Center

The felsic rocks (rocks rich in silica/quartz) found at the Acasta River in Canada, are the Earth’s oldest rocks, although there are older mineral crystals. Scientists have long known that the Acasta rocks are different to the majority of felsic rocks we see today, such as the granites widely used as a building or decorative material. Now a group of scientists from Australia and China have modelled the formation of the oldest Acasta felsic rocks and found that they could only have been formed at low pressures and very high temperatures.

Scientists believe that the primitive crust largely comprised dark, silica-poor mafic rocks, so there has been a question over how the Acasta River felsic rocks could have formed.

“Our modelling shows that the Acasta River rocks derived from the melting of pre-existing iron-rich basaltic rock, which formed the uppermost layers of crust on the primitive Earth”, said team leader Tim Johnson, from Curtin University, Perth.

“We used phase equilibria and trace element modelling to show that the Acasta River rocks were produced by partial melting of the original mafic rocks at very low pressures. It would have needed something special to produce the 900°C temperatures needed to generate these early felsic rocks at such low pressures, and that probably means a drastic event, most likely the intense heating caused by meteorite bombardment.

We estimate that rocks within the uppermost 3km of mafic crust would have been melted in producing the rocks we see today. We think that these ancient felsic rocks would have been very common, but the passage of 4 billion years, and the development of plate tectonics, means that almost nothing remains.

We believe that these rocks may be the only surviving remnants of a barrage of extraterrestial impacts which characterized the first 600 million years of Earth History”.

The Acasta River is part of the Slave Craton formation in Northern Canada, north of Yellowknife and the Great Slave Lake. The area is the homeland of the Tlicho people, which led to the geologists who discovered the rocks giving them the name “Idiwhaa”, derived from the Tlicho word for ancient.

Commenting, Dr Balz Kamber (Trinity College Dublin) said that “The idea of making felsic melts by large or giant impacts seems plausible considering the high-energy nature of these events and the pockmarked ancient surfaces of other inner Solar System planets and moons. However, the implied pressure-temperature regime might also permit melting of shallow crust below a super-heated impact melt sea. In other words, an indirect consequence of the impact itself”.

Source: Goldschmidt Conference [August 13, 2018]



200-million year old Pterosaur ‘built for flying’

Scientists on Monday unveiled a previously unknown species of giant pterosaur, the first creatures with a backbone to fly under their own power.

200-million year old Pterosaur 'built for flying'
Artist’s interpretation of the newly discovered pterosaur snacking on a primitive crocodylomorph
known as a sphenosuchian [Credit: Josh Cotton]

Neither dino nor bird, pterosaurs — more commonly known as pterodactyls — emerged during the late Triassic period more than 200 million years ago and lorded over primeval skies until a massive space rock slammed into Earth, wiping out the dinosaurs and most other forms of life some 65 million years ago.

The newly discovered member of the family, identified through remains found in northeastern Utah, had a wing-span of 1.5 metres (five feet) and 112 teeth, including fang-like spikes sticking out near the snout.

A jutting lower jaw suggests a pelican-like pouch, perhaps to scoop up fish and unsuspecting small reptiles.

“They are delicately framed animals that are built for flying,” said Brooks Britt, a paleontologist at Brigham Young University in Utah and lead author of a study in Nature Ecology & Evolution.

Caelestiventus hanseni — roughly, “heavenly wind” — is probably the most complete skeletal remains of a pterosaur ever found.

“Most pterosaurs bones look like road-kill,” Britt told AFP, noting that there are only 30-odd specimens worldwide from the Triassic period which lasted some 51 million years.

200-million year old Pterosaur 'built for flying'
Factfile on Caelestiventus hanseni a new species of flying reptiles, known as Pterosaurs,
discovered in US state of Utah [Credit: AFP/Laurence CHU]

By contrast, the new specimen comprises dozens of intact bones and teeth, along with an entire brain casing.

The wings are in fact skin membranes largely held up by the fourth “finger”, or digit, of their forelimbs. Huge sockets suggest C. hanseni had “fantastic eyesight”, said Britt.

When not soaring in search of a meal, it walked on all fours with its wings folded vertically.

The fossil remains are still encased in sandstone, but scientists generated accurate 3-D images and models of each bone using CAT-scan technology.

The site where C. hanseni was unearthed, known to fossil hunters as Saints & Sinners, reveals a dramatic story of survival and local extinction in the face of climate change, the researchers said.

The rocks it was found in were part of an oasis in a two-million square kilometre (775,000 square mile) desert covered with giant sand dunes.

200-million year old Pterosaur 'built for flying'
Saints and Sinners quarry, in Utah along the Colorado boarder, where the paleontologists
found the pterosaur fossils [Credit: Brooks B. Britt Brigham Young University]

“During droughts, large numbers of animals — including pterosaurs, predatory dinosaurs and crocodylomorphs — were drawn to the pond in the middle of the oasis, where they died as water dried up,” said Britt.

The result was a treasure trove of more than 18,000 bones and fragments from dozens of water-starved animals.

C. hanseni is not the biggest pterosaur ever found, but was likely the largest of its era, especially for a desert environment.

It also predates other desert-dwelling specimens by about 65 million years. Pterosaurs from the same period found so far came from ancient coastal areas in what is now Europe and Greenland.

That the high-flying creatures were spread across much of the globe may have helped them survive the end-of-Triassic mass extinction, which wiped out half of the species on land and in the sea.

Author: Marlowe Hood | Source: AFP [August 13, 2018]



New study reveals evidence of how Neolithic people adapted to climate change

Research led by the University of Bristol has uncovered evidence that early farmers were adapting to climate change 8,200 years ago.

New study reveals evidence of how Neolithic people adapted to climate change
In situ pottery at the archaeological site of Çatalhöyük [Credit: Çatalhöyük Research Project]

The study, published in the journal Proceedings of the National Academy of Sciences, centred on the Neolithic and Chalcolithic city settlement of Çatalhöyük in southern Anatolia, Turkey which existed from approximately 7500 BC to 5700 BC.

During the height of the city’s occupation a well-documented climate change event 8,200 years ago occurred which resulted in a sudden decrease in global temperatures caused by the release of a huge amount of glacial meltwater from a massive freshwater lake in northern Canada.

Examining the animal bones excavated at the site, scientists concluded that the herders of the city turned towards sheep and goats at this time, as these animals were more drought-resistant than cattle. Study of cut marks on the animal bones informed on butchery practices: the high number of such marks at the time of the climate event showed that the population worked on exploiting any available meat due to food scarcity.

The authors also examined the animal fats surviving in ancient cooking pots. They detected the presence of ruminant carcass fats, consistent with the animal bone assemblage discovered at Çatalhöyük. For the first time, compounds from animal fats detected in pottery were shown to carry evidence for the climate event in their isotopic composition.

Indeed, using the “you are what you eat (and drink)” principle, the scientists deducted that the isotopic information carried in the hydrogen atoms (deuterium to hydrogen ratio) from the animal fats was reflecting that of ancient precipitation. A change in the hydrogen signal was detected in the period corresponding to the climate event, thus suggesting changes in precipitation patterns at the site at that time.

The paper brings together researchers from the University of Bristol’s Organic Geochemistry Unit (School of Chemistry) and the Bristol Research Initiative for the Dynamic Global Environment (School of Geographical Sciences).

Co-authors of the paper include archaeologists and archaeozoologists involved in the excavations and the study of the pottery and animal bones from the site.

Dr Mélanie Roffet-Salque, lead author of the paper, said: “Changes in precipitation patterns in the past are traditionally obtained using ocean or lake sediment cores.

“This is the first time that such information is derived from cooking pots. We have used the signal carried by the hydrogen atoms from the animal fats trapped in the pottery vessels after cooking.

“This opens up a completely new avenue of investigation – the reconstruction of past climate at the very location where people lived using pottery.”

Co-author, Professor Richard Evershed, added: “It is really significant that the climate models of the event are in complete agreement with the H signals we see in the animal fats preserved in the pots.

“The models point to seasonal changes farmers would have had to adapt to – overall colder temperatures and drier summers – which would have had inevitable impacts on agriculture.”

Source: University of Bristol [August 13, 2018]



In a massive region of space, astronomers find far fewer galaxies than they expected

University of California astronomers, including three from UCLA, have resolved a mystery about the early universe and its first galaxies.

In a massive region of space, astronomers find far fewer galaxies than they expected
Computer simulation of the distribution of matter in the universe. Orange regions host galaxies; blue structures are gas
and dark matter. A University of California study demonstrated that opaque regions of the universe are like the large
 voids in the galaxy distribution in this image because too little light from the galaxies is able to reach such
 regions and render them transparent [Credit: TNG Collaboration]

Astronomers have known that more than 12 billion years ago, about 1 billion years after the Big Bang, the gas in deep space was, on average, much more opaque than it is now in some regions, although the opacity varied widely from place to place. But they weren’t sure about what caused those variations.

To learn why the differences occurred, the astronomers used one of the world’s largest telescopes, the Subaru telescope on Mauna Kea in Hawaii, to search for galaxies of young stars in an exceptionally large region of space — 500 million light-years across — where they knew the intergalactic gas was extremely opaque.

If the region had an unusually small number of galaxies, the scientists would be able to conclude that starlight could not penetrate as far as expected through the intergalactic gas; if it had an unusually large number of galaxies, the implication would be that the region had cooled significantly over the previous several hundred million years. (Having few galaxies in a region would mean not only that there was less light created by those galaxies, but also that even more opaque gas was being formed, so the light could not travel as far as astronomers had expected.)

“It was a rare case in astronomy where two competing models, both of which were compelling in their own way, offered precisely opposite predictions, and we were lucky that those predictions were testable,” said Steven Furlanetto, a UCLA professor of astronomy and a co-author of the research.

The researchers found that region contains far fewer galaxies than expected — clear evidence that starlight could not get through. The paucity of galaxies could be the reason this region is so opaque.

“It is not that the opacity is a cause of the lack of galaxies,” Furlanetto said. “Instead, it’s the other way around.”

They concluded that because the gas in deep space is kept transparent by ultraviolet light from galaxies, fewer nearby galaxies might make it murkier.

The research is published in the Astrophysical Journal.

In the first billion years after the Big Bang, ultraviolet light from the first galaxies filled the universe with gas in deep space. This would have occurred earlier in regions with more galaxies, the astronomers concluded. The astronomers plan to further study whether the void and others like it will reveal clues about how the first generations of galaxies illuminated the universe during that early period. Furlanetto said the astronomers hope that studying the interplay of galaxies and gas in deep space will reveal more about how the intergalactic ecosystem took shape during that period of the early universe.

Source: University of California, Los Angeles [August 14, 2018]



Origins and spread of Eurasian fruits traced to the ancient Silk Road

Studies of ancient preserved plant remains from a medieval archaeological site in the Pamir Mountains of Uzbekistan have shown that fruits, such as apples, peaches, apricots, and melons, were cultivated in the foothills of Inner Asia. The archaeobotanical study, conducted by Robert Spengler of the Max Planck Institute for the Science of Human History, is among the first systematic analyses of medieval agricultural crops in the heart of the ancient Silk Road. Spengler identified a rich assemblage of fruit and nut crops, showing that many of the crops we are all familiar with today were cultivated along the ancient trade routes.

Origins and spread of Eurasian fruits traced to the ancient Silk Road
Excavations at the medieval site of Tashbulak are co-directed by Michael Frachetti and Farhad Maksudov;
research at the site is ongoing [Credit: Robert Spengler]

The Silk Road was the largest vector for cultural spread in the ancient world – the routes of exchange and dispersal across Eurasia connected Central Asia to the rest of the world. These exchange routes functioned more like the spokes of a wagon wheel than a long-distance road, placing Central Asia at the heart of the ancient world. However, most historical discussions of the ancient Silk Road focus on the presence of East Asian goods in the Mediterranean or vice versa.

The present study, published in PLOS ONE, looks at archaeological sites at the center of the trans-Eurasian exchange routes during the medieval period, when cultural exchange was at its highest. Additionally, scholarship has focused on a select handful of goods that moved along these trade routes, notably silk, metal, glass, and pastoral products.

However, historical sources and now archaeological data demonstrate that agricultural goods were an important commodity as well. Notably, higher value goods, such as fruits and nuts, spread along these exchange routes and likely contributed to their popularity in cuisines across Europe, Asia, and North Africa today. Ultimately this study helps demonstrate how the Silk Road shaped what foods we all eat today.

Our everyday fruits and nuts have their roots in the Silk Road

Spengler analyzed preserved ancient seeds and plant parts recovered from a medieval archaeological site in the foothills of the Pamir Mountains of eastern Uzbekistan. The site, Tashbulak, is currently under excavation by a collaborative international Uzbek/American project co-directed by Michael Frachetti, of Washington University in St. Louis, and Farhod Maksudov, of the Institute for Archaeological Research, Academy of Sciences in Tashkent, Uzbekistan.

Origins and spread of Eurasian fruits traced to the ancient Silk Road
Vendors in every Central Asian bazaar sell a diverse array of melons. These two women in the Bukhara bazaar
are selling a variety akin to the famous Hami melons of Xinjiang. There is a great deal of regional
pride associated with specific varieties of landrace melons [Credit: Robert Spengler]

The plant remains recovered from this site represent one of the first systematic studies of the crops that people were growing along the Silk Road. In the article, archaeobotanical data are contrasted with historical and other archaeological evidence in order to discuss the timing and routes of spread for the cultivated plants. These plant remains date to roughly a millennium ago and include apple, grape, and melon seeds, peach and apricot pits, and walnut and pistachio shells.

This study helps demonstrate that there was a rich and diverse economy in Central Asia during this period, including a wide array of cultivated grains, legumes, fruits, and nuts. The site of Tashbulak is located at 2100 meters above sea level, above the maximum elevations at which many of these fruit trees can be grown, suggesting that the fruit remains recovered at the site were carried from lower elevations. Historical sources attest to the importance of fresh and dried fruits and nuts as a source of commerce at market bazaars across Inner Asia.

These trade routes facilitated the spread of many of our most familiar crops across the ancient world. For example, the earliest clear archaeological evidence for peaches and apricots comes from eastern China, but they were present in the Mediterranean by the Classical period. Likewise, grapes originated somewhere in the broader Mediterranean region, but grape wine was a popular drink in the Tang Dynasty. We can now say that all of these fruit crops were prominent in Central Asia by at least a millennium ago, likely much earlier.

As Spengler points out, “The ecologically rich mountain valleys of Inner Asia fostered the spread of many cultivated plants over the past five millennia and, in doing so, shaped the ingredients in kitchens across Europe and Asia.”

Central Asia is a key homeland and dispersal point for many important arboreal crops, such as apples and pistachios

Spengler also points out that many economically important fruit crops originated in the foothill forests of eastern Central Asia. For example, studies suggest that much of the genetic material for our modern apples comes from the Tien Shan wild apples of southeastern Kazakhstan, and pistachios originated in southern Central Asia.

Origins and spread of Eurasian fruits traced to the ancient Silk Road
Historical sources praise the quality of fruits from specific regions or orchards in Central Asia, such as the golden
peaches or Samarkand, the Hami melons, or the mare’s nipple grapes. Many unique varieties of fruits are
 cultivated in Central Asia today, including these small Bukharan apricots, which are primarily
grown for their nutty seeds [Credit: Robert Spengler]

Despite the importance of these arboreal crops in the modern world economy, relatively limited scholarly focus has gone into the study of their origins and dispersal. The data from Tashbulak are an important contribution to that study. The article shows the importance of archaeological research in Central Asia, highlighting its role in the development of cultures across the ancient world.
In his forthcoming book, “Fruit from the Sands,” Spengler traces the spread of domesticated plants across Central Asia. In the book, set to hit shelves in April 2019, he states, “The plants in our kitchens today are archaeological artifacts, and part of the narrative for several of our favorite fruits and nuts starts on the ancient Silk Road.”

Excavations at Tashbulak are ongoing, with support from Washington University in St. Louis, the Max von Berchem Foundation, and the National Geographic Society. Over the next few years, the research team expects that their research will better elucidate the nature of interaction and contact in the mountains of Central Asia.

Frachetti notes, “The insights gained from this archaeobotanical study help link the juicy details of ancient cuisine to our modern tables, and in doing so highlights the long-term impact of interactions between diverse communities and regions on a global scale.”

Source: Max Planck Institute for the Science of Human History [August 14, 2018]



Unpublished Egyptian texts reveal new insights into ancient medicine

The University of Copenhagen in Denmark is home to a unique collection of Ancient Egyptian papyrus manuscripts.

Unpublished Egyptian texts reveal new insights into ancient medicine
Instructions for a 3,500-year-old pregnancy test [Credit: Carlsberg Papyrus Collection/University of Copenhagen]

A large part of the collection has not yet been translated, leaving researchers in the dark about what they might contain.

“A large part of the texts are still unpublished. Texts about medicine, botany, astronomy, astrology, and other sciences practiced in Ancient Egypt,” says Egyptologist Kim Ryholt, Head of the Carlsberg Papyrus Collection at the University of Copenhagen, Denmark.

An international team of researchers are now translating the previously unexplored texts, which according to one of the researchers, contain new and exciting insights into Ancient Egypt.

“It’s totally unique for me to be able to work with unpublished material. It doesn’t happen in many places around the world,” says Ph.D. student Amber Jacob from the Institute for the Study of The Ancient World at New York University, USA. She is one of four Ph.D. students working on the unpublished manuscripts held in Copenhagen.

The Egyptians knew about kidneys

Jacob’s research focuses on the medical texts from the Tebtunis temple library, which existed long before the famous Library of Alexandria, up until 200 BCE.

In one of the texts, she has found evidence that Ancient Egyptians knew about the existence of kidneys.

“It’s the oldest known medical text to discuss the kidneys. Until now, some researchers thought that the Egyptians didn’t know about kidneys, but in this text we can clearly see that they did,” says Jacob.

Unpublished Egyptian texts reveal new insights into ancient medicine
This little piece of papyrus is believed to contain a type of oracle question. The author has written
 two possible outcomes for a situation and asked the gods to indicate which one was the truth
[Credit: The Papyrus Carlsberg Collection/ University of Copenhagen]

The papyri also reveal insights into the Egyptian view on astrology.

“Today, astrology is seen as a pseudoscience, but in antiquity it was different. It was an important tool for predicting the future and it was considered a very central science,” says Ryholt.

“For example, a king needed to check when was a good day to go to war,” he says.

Astrology was their way of avoiding going to war on a bad day, such as when the celestial bodies were aligned in a particular configuration.

Egyptians’ contribution to science

The unpublished manuscripts provide a unique insight to the history of science, says Ryholt.

“When you hear about the history of science, the focus is often on the Greek and Roman material. But we have Egyptian material that goes much further back. One of our medical texts was written 3,500 years ago when there was no written material on the European continent,” he says.

Analysing this 3,500-year-old text is the job of Ph.D. student, Sofie Schiødt from the University of Copenhagen.

One side of the manuscript describes unusual treatments for eye diseases, says Schiødt.

Papyrus text discovered in Germany

The other side, describes the Ancient Egyptian equivalent of a pregnancy test and scan.

“The text says that a pregnant woman should pee into a bag of barley and a bag of wheat. Depending on which bag sprouts first reveals the sex of her child. And if neither of the bags sprout then she wasn’t pregnant,” says Schiødt.

Unpublished Egyptian texts reveal new insights into ancient medicine
Sofie Schiødt in front of a 3,500-year-old medical papyrus [Credit: Mikkel Andreas Beck]

Her research reveals that the ideas recorded in the Egyptian medical texts spread far beyond the African continent.

“Many of the ideas in the medical texts from Ancient Egypt appear again in later Greek and Roman texts. From here, they spread further to the medieval medical texts in the Middle East, and you can find traces all the way up to premodern medicine,” she says.

The same pregnancy test used by Egyptians is referred to in a collection of German folklore from 1699.

“That really puts things into perspective, as it shows that the Egyptian ideas have left traces thousands of years later,” says Schiødt.

“Every single contribution is important”

Translating the unpublished texts is important work, according to Egyptologist Hans-Werner Fischer-Elfert from the Department of Egyptology, University of Leipzig, Germany.

“We still have a very fragmented knowledge of the natural sciences in Ancient Egypt. Therefore every singly contribution is important,” he says.

“Today there are still a number of sources that theoretically were known by scientists but still sat dormant in various collections around the world without anyone looking at them in detail. Now the time has come to recognise them.”

Author: Lise Brix | Source: ScienceNordic [August 14, 2018]

This article was originally published on ScienceNordic. Read the original article here.



HiPOD (15 August 2018): Semi-Sinuous Ridge and Stratified…

HiPOD (15 August 2018): Semi-Sinuous Ridge and Stratified Material in Arabia Terra 

   – Looks like inverted stream channels that contributed to a lake or pond, with stratified sedimentary rock units in the depression. Important imaging for understanding how to best distinguish cratered, erosion-resistant sedimentary rock units from volcanic and impact melt rocks. (275 km above the surface. Black and white is less than 5 km across; enhanced color is less than 1 km)

NASA/JPL/University of Arizona

Ty Mawr Passage Grave, Menai Straits, Anglesey, 14.8.18.Another…

Ty Mawr Passage Grave, Menai Straits, Anglesey, 14.8.18.

Another first visit for me. This sad pile of stones is all that remains of a once impressive passage grave. Situated near the road close to the Menai Straits, this would have occupied a visible position across the straits in the distant past. The large capstone and several key stones are there but it is hard to discern its original structure now.

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2018 August 15 Launch of the Parker Solar Probe Image Credit…

2018 August 15

Launch of the Parker Solar Probe
Image Credit & Copyright: John Kraus

Explanation: When is the best time to launch a probe to the Sun? The now historic answer – which is not a joke because this really happened this past weekend – was at night. Night, not only because NASA’s Parker Solar Probe’s (PSP) launch window to its planned orbit occurred, in part, at night, but also because most PSP instruments will operate in the shadow of its shield – in effect creating its own perpetual night near the Sun. Before then, years will pass as the PSP sheds enough orbital energy to approach the Sun, swinging past Venus seven times. Eventually, the PSP is scheduled to pass dangerously close to the Sun, within 9 solar radii, the closest ever. This close, the temperature will be 1,400 degrees Celsius on the day side of the PSP’s Sun shield – hot enough to melt many forms of glass. On the night side, though, it will be near room temperature. A major goal of the PSP’s mission to the Sun is to increase humanity’s understanding of the Sun’s explosions that impact Earth’s satellites and power grids. Pictured is the night launch of the PSP aboard the United Launch AlliancesDelta IV Heavy rocket early Sunday morning.

∞ Source: apod.nasa.gov/apod/ap180815.html

Diverse symbionts of reef corals have endured since ‘age of dinosaurs’

Coral-algal partnerships have endured numerous climate change events in their long history, and at least some are likely to survive modern-day global warming as well, suggests an international team of scientists.

Diverse symbionts of reef corals have endured since 'age of dinosaurs'
Reef corals comprise thousands or millions of genetically identical algal polyps, which remain attached to each other
 to produce massive colonies. This close-up shows Orbicella, an important reef-building coral in the Caribbean.
The species and its symbiosis with micro-algae has been studied extensively [Credit: Penn State]

The team’s conclusion is based on the finding that the relationship between corals and the mutualistic micro-algae that enable them to build reefs is considerably older and more diverse than previously assumed.

“Past estimates placed the initiation of these symbiotic relationships at 50 to 65 million years ago,” said Todd LaJeunesse, associate professor of biology, Penn State. “Our research indicates that modern corals and their algal partners have been entwined with each other for much longer — since the time of the dinosaurs, approximately 160 million years ago. During their long existence, they have faced severe episodes of environmental change, but have managed to bounce back after each one.”

According to LaJeunesse, the micro-algae, commonly called zooxanthellae — of the dinoflagellate family Symbiodiniaceae — live inside the cells of corals, allowing them to acquire energy from sunlight and to build the massive, economically valuable reef formations upon which countless marine organisms rely for habitat.

Diverse symbionts of reef corals have endured since 'age of dinosaurs'
Corals, like the branching Acropora featured here, are animals that construct massive reef frameworks and are the basis
of coral reef ecosystems. These corals ultimately depend on micro-algal symbionts that capture light from the sun
and covert it to nutrients for the host coral’s growth and survival [Credit: Tobin T. Smith]

“The fossil record shows that today’s reef-building corals exploded in diversity around 160 million years ago,” said LaJeunesse. “Finding that the origin of the algal symbionts corresponds to major increases in the abundance and diversity of reef-building corals implies that the partnership with Symbiodiniaceae was one of the major reasons for the success of modern corals.”

The team used genetic evidence — including DNA sequences, phylogenetic analyses and genome comparisons — to calculate the micro-algae’s approximate age of origin. They also used classical morphological techniques in which they compared visual characteristics of these symbionts using light and electron microscopy, along with computer modeling and other methods, to discover that in addition to being older, the algae family is far more diverse than previously perceived. The results appear online in Current Biology.

“Presently, numerous algal lineages, called clades, are lumped into just one genus,” said John Parkinson, postdoctoral researcher, Oregon State University. “Using genetic techniques, we provide evidence that the family actually comprises at least 15 genera, including hundreds and possibly thousands of species worldwide.”

Diverse symbionts of reef corals have endured since 'age of dinosaurs'
Because they are tiny round spheres with few features to tell them apart, the symbiotic microscopic algae of corals were
once thought to be a single species found in all reef-building corals. These symbionts are now recognized to be
a group that comprises hundreds and possibly thousands of species that can be sorted into at least 15 genera
[Credit: Todd LaJeunesse]

This is important, he explained, because some micro-algal symbionts have characteristics that make them more resilient to changes in the environment than other symbionts.

“The updated naming scheme offers a clear framework to identify different symbionts,” said Parkinson. “Accurate taxonomy (the identification and naming of species) is a critical step in any biological research. This is especially true for studies attempting to understand how the partnership between reef corals and their micro-algae, which are needed for survival and growth, may adapt to climate change. For example, when many corals are exposed to high temperatures they lose their symbiotic algae and die. Others are far more tolerant of heat, and some of this resilience is based on the species of algae they have.”

Parkinson noted that the team has been working for close to a decade to modernize coral symbiont taxonomy in order to improve communication among scientists and advance future research on reef corals.

Diverse symbionts of reef corals have endured since 'age of dinosaurs'
The relationship between corals and an unusual group of micro-algae called dinoflagellates in the family Symbiodiniaceae
forms the basis of coral reef ecosystems. The flagellated stage — featuring a whip-like structure that enables the
 organism to swim — is featured here with the image of a surface of a coral showing polygonal-shaped
polyps in the background [Credit: Todd LaJeuness, Hae Jin Jeong/Penn State]

“Until now, studies on the physiology and ecology of these algae attempted to compare apples to apples,” said Parkinson. “Considering how different some of them are, we now recognize that often we were comparing apples to oranges. These changes will help researchers to think more accurately about the comparisons they are making in experiments.”

Author: Sara LaJeunesse | Source: Penn State [August 09, 2018]



Primate study offers clues to evolution of speech

New research examining the brains and vocal repertoires of primates offers important insight into the evolution of human speech.

Primate study offers clues to evolution of speech
New research examining the brains and vocal repertoires of primates offers important insight
 into the evolution of human speech [Credit: Sergey Uryadnikov/Shutterstock]

The vocal tract and larynx is similar in form and function amongst virtually all terrestrial mammals, including humans. However, relative to humans, non-human primates produce an extremely limited range of vocalisations.

Published in the journal Frontiers in Neuroscience, the new research investigates whether the reason primates are incapable of producing speech is because they lack the brain mechanisms needed to control and coordinate vocal production.

The study focused on two particular features of the brain: the cortical association areas that govern voluntary control over behaviour; and the brainstem nuclei that are involved in the neural control of muscles responsible for vocal production.

The academics, from Anglia Ruskin University and Stony Brook University, found a positive correlation between the relative size of cortical association areas and the size of the vocal repertoire of primates, which can range from just two call types in pottos to at least 38 different calls made by bonobos.

Lead author Dr Jacob Dunn, Senior Lecturer in Zoology at Anglia Ruskin University, said: “This study shows, for the first time, a significant positive correlation between the vocal repertoire and the relative size of the parts of the brain responsible for voluntary control over behaviour.

“Cortical association areas are found within the neocortex and are key to the higher cognitive processing capacities considered to be the foundation for the complex forms of behaviour observed in primates. Interestingly, the overall size of the primate’s brain was not linked to the vocal repertoire of that species, only the relative size of these specific areas.

“We also found a positive relationship between the relative volumes of the cortical association areas and the hypoglossal nucleus in apes, both of which are significantly bigger in these species. The hypoglossal nucleus is associated with the cranial nerve that controls the muscles of the tongue, thus suggesting increased voluntary control over the tongue in our closest relatives.

“By understanding the nature of the relationship between vocal complexity and brain architecture across non-human primates, we hope we are beginning to identify some of the key elements underlying the evolution of human speech.”

Source: Anglia Ruskin University [August 09, 2018]



Ice sheets of the last ice age seeded the ocean with silica

New research led by glaciologists and isotope geochemists from the University of Bristol has found that melting ice sheets provide the surrounding oceans with the essential nutrient silica.

Ice sheets of the last ice age seeded the ocean with silica
Researchers from the Bristol Glaciology Centre look over the vast Greenland Ice Sheet, which stretches beyond the
 horizon, during a field campaign lasting over three months in 2015. The researchers camped in a remote
region of Greenland, monitoring a large meltwater river and taking samples to look at the silica
concentration and isotopic signature [Credit: Dr Jon Hawkings, University of Bristol]

Silica is needed by a group of marine algae (the microscopic plants of the oceans) called diatoms, who use it to build their glassy cell walls (known as frustules).

These plankton take up globally significant amounts of carbon – they remove carbon dioxide from the atmosphere via photosynthesis, and act as a natural carbon sink when they die and fall to the bottom of the ocean – and form the base of the marine food chain.

The study, published in the journal Nature Communications, suggests that glacial meltwater, both in the present and during past ice ages, contains silica that could be useful in sustaining the growth of diatoms in the oceans around ice sheets, which are home to economically important fisheries and marine life.

The researchers show that the silica in glacial meltwaters from the Greenland Ice Sheet has a distinctive isotopic signature, different to the that found in other rivers.

Researchers have previously found that diatoms and sponges (which build their skeletons from silica) gradually buried in ocean sediments since the last ice age have a different silicon isotopic signature to their modern-day relatives.

This lighter isotopic signature was thought to be the result of changing diatom activity and ocean currents during and between ice ages. However, researchers now think that a change in the isotopic signature of the river waters supplied to the ocean might account for these shifts.

Dr Jon Hawkings, lead author of the study from the University of Bristol’s School of Geographical Sciences,  Bristol Glaciology Centre and Cabot Institute for the Environment said: “In this study we wanted to find out if silica in glacial meltwaters from a large ice sheet (Greenland) has a distinctive isotopic signature.

Ice sheets of the last ice age seeded the ocean with silica
Vast quantities of milky glacial meltwaters sourced from Greenland Ice Sheet make their way toward the ocean.
The milky colour of meltwaters is caused by the large quantities of finely ground rock flour
carried by the meltwater [Credit: Dr Jon Hawkings, University of Bristol]

“If it does, then the huge quantities of meltwater coming from melting ice sheets during the deglaciation could account for some of the change in ocean silicon isotopic signature that have been recorded previously. Rapid ice sheet melting during the last ice age led to periods of sea level rise great than 3 cm per year (compared to around 0.3 cm per year at present).

“At peaks, ice sheets melting an estimated 25,000 km3 of water was entering the oceans from melting ice sheets every year – this is more than three times the amount of water currently flowing from the Amazon river.

“If silica carried by ice sheet meltwaters does have a distinctive isotopic signature, then this reshapes how important ice sheets, and large deglaciation events, are in global biogeochemical cycles.”

Researchers examined silica concentrations in meltwaters and the silicon isotopic signature of those meltwaters (referred to as δ30Si, which we’re using as a “marker” of glacial silica), alongside a computer model using this data, and results from a marine sediment core off the coast of Iceland which shows distinctive changes in the silicon isotopic composition of sponges during periods of ice sheet collapse. They wanted to determine:

– If glacial meltwaters have a distinct silica signal that can be used to trace inputs into the ocean

– If there were any changes to the isotopic signal over the course of a summer melt period (which might reflect where the silica comes from within a glacier)

– To predict the impact from rapidly melting ice sheets of the last ice age on marine ecosystems

Ice sheets of the last ice age seeded the ocean with silica
Glacial meltwaters carrying silica with a distinctive isotopic signature flow into marine ecosystems,
where microscopic algae known as diatoms use the silica to build their glassy cell walls
[Credit: Dr Jon Hawkings, University of Bristol]

The study concluded that glaciers and ice sheets are an under-appreciated component of the silica cycle, exporting large quantities of reactive silica into the ocean, which could be used by diatoms. This might, say researchers, have major implications for the health of marine siliceous organisms during periods of significant ice cover and rapid deglaciation.

The study showed ice sheet runoff has the lightest silicon isotopic composition ever measured in running water – values for glacial meltwaters are much lower than any measurements of non-glacial riverine runoff.

Using this data combined with a simple computer model of the ocean since the last ice age maximum (around 21,000 years ago) the study predicts that up to a third of the observed changes in the silicon isotopic signature of siliceous organisms can be explained by the melting of the massive ice sheets that at their peak covered up to 30 percent of the land surface, including much of North America and Europe, including much of the United Kingdom.

The isotopic composition also helps to explain that meltwater is sourced from further into the ice sheet as the annual melting period progresses, flushing liquid water stored hundreds of meters under the ice.

Dr Hawkings added: “Our findings re-frame the traditional view of the importance of ice sheets in biogeochemical cycles, specifically of the silica cycle.

“Previously the huge quantities of water and sediment delivered from the ice sheets of the last ice age wasn’t fully considered as having a significant impact on marine chemistry and biology, but our study points that this is likely an oversight.

“Our interpretation of a number of other isotopic systems, and of changes to biogeochemical cycles since the last glacial maximum therefore likely needs re-evaluating.”

There is still a lot of work needed to discover the importance of ice sheets in global nutrient cycles.

The research team will now work to establish if other glaciers carry significant quantities of isotopically distinctive silica to the oceans, by visiting a range of glaciers around Greenland (and further afield) to see if this relationship holds.

Source: University of Bristol [August 10, 2018]



Units of Being Proteins and DNA live in symbiosis – in a cell,…

Units of Being

Proteins and DNA live in symbiosis – in a cell, one can’t survive without the other. The work-horses of the cell, proteins are transporters, catalysts and signal carriers, their functions underpinned by DNA carrying an intricate code that dictates the sequence of amino acids in each protein. A hormone named insulin was the first protein to have its amino acid sequence uncovered, the product of over ten years of patient work by Frederick Sanger – born on this day in 1918 – who used ‘Sanger’s reagent’ to break up the long amino acid chains of the protein and meticulously sequence each fragment. Awarded his first Nobel Prize in 1958 for this work on protein structure, Sanger’s second Nobel Prize was awarded in 1980 for work on the other building block of life – DNA, where, by inventing the ‘Sanger method’ of reading the genetic code, Sanger revolutionised the field of genetics for years to come.

Read more here about Fred Sanger at the MRC Laboratory of Molecular Biology

Written by Ellie McLaughlin

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Tyddyn-Bach Standing Stone, nr Bryn Celli Ddu Burial Chamber,…

Tyddyn-Bach Standing Stone, nr Bryn Celli Ddu Burial Chamber, Anglesey, 14.8.18.

Another new site for me, this solitary standing stone sits amid a pile of potentially unrelated stones. It is unknown whether these formed a related monument or just the product of land clearance. The tree has apparently grown up in the last fifteen years. The stone sits within view of the well known Bryn Celli Ddu Burial Chamber only a few fields away.

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    Солнечное затмение 14 декабря 2020 года  — полное  солнечное затмение  142  сароса , которое лучше всего будет видно в юго-восточной час...